Cartographer's Toolkit

Map Making Tips, Tricks, and Inspiration

Map Take-Aways

April 20th, 2017

One key to cartographic success is employing a deft mixture of subtle and forthright elements in order to achieve that most difficult of harmonizations: effortless yet highly informative communication. Here’s an example that came up in my twitter thread just a few moments ago:

Here we see several elements that help to achieve the right balance:

  • Masked basemap: focuses reader attention on the area of interest while also providing geographic context.
  • Gray titling: “DISTRICT OF COLUMBIA” is in a light gray color, which minimizes its appearance despite its being diffused across the legend box. You see this often with titles in all-caps.
  • Black titling: “LAND USE PLAN” is what the map author really wants you to read first, so this is both in black and all-caps.
  • Legend box in light gray: since the light-gray text elements could blend with the light-gray masked basemap, the legend box is needed in this case, but it is kept subtle.
  • Bold colors for the landuses: landuse plan maps are notorious for their cartographic difficulty in that the combination of landuses and basemap information can make for an entirely cluttered aesthetic. Making the landuses the number one focus point was a good idea for this map.
  • Polygon boundary colors in slightly darker shades: slightly darker polygon boundaries in the same hue as the polygons helps to define the boundaries of the polygons while not overwhelming the map. Black boundaries on all polygons would not have served well here.

On the importance of rapid information transmittal

June 30th, 2016

While reading this news piece on bitcoin this morning I came across this chart:

Just the top portion of the chart

Just the top portion of the chart

Since this was some quick pre-work reading on a subject I follow from time to time but don’t study in-depth, I spent only about 5 seconds looking at the chart before I determined that it would be too much effort to understand. I thought to myself, “I know this chart is probably revealing some amazing truths and is well-done, because I trust the New York Times Graphics Department, but I’m not going to take the time to understand it this morning.”

This was a huge reminder to myself that this is precisely the way that 99% of map readers react to complex maps that they see. The lesson? If you want the majority of the readers to understand something at a glance, keep it as close to a normal, popularly familiar, map style as possible. But, you say that you are a leader in the cartography field who’s job it is to come up with fancy new visualizations?

While it may be true that only the lead dog sees the landscape (hat tip Alan Weiss), the lead dog has to navigate and interpret that landscape for its pack. Likewise, a cartography leader needs to make sure that his/her followers understand the map quickly and clearly.

Here’s a map-based example. I think that the map shown here is a little too strange to invite a quick interpretation for the reader overall. Furthermore, the legend info pertaining to the colors is actually found in the article text whereas it would have been nice to have it also accompanying the map:

Tax map

Tax map


(Please note: I never want to discourage innovation nor do I ever want to discourage individuals from publishing for fear of getting critiques like this. While I am critiquing the amount of time it takes to interpret this map I do like the varying transparency, the subtle background color, the thin white lines to unobtrusively denote county boundaries, and the use of orange as a counterpoint to the blue. There are many successful things about the map and I always think to myself that it could just be me having trouble with the other bits and that there’s a possibility everyone else completely understands this thing at a moment’s glance. TLDR: this is just one persons opinion and likely to be wrong.)

So what do you do if you still want to use one or many innovative visualization techniques in your cartography?

Answer 1: That’s perfectly okay if the map can be interpreted very quickly despite the fact that it looks different than what we’re used to. comes to mind as an excellent example of a new technique that was actually easier to understand than any prior techniques for showing wind.

Answer 2: Leave the more complex cartographic innovation for media that invites longer perusal such as, but not by any means limited to:

  • Map focused books
  • The Sunday magazine instead of the regular paper
  • Scholarly articles
  • Twitter map nerd feeds
  • Advanced conference tracks
  • Github repositories
  • Educational tutorials



Visual thresholds for cartographic features

December 4th, 2015

I was surfing posts on GIS stack exchange, as one does, when I came across this post featuring a French textbook figure on cartographic visual constraints. It’s a handy little reference piece on minimum point sizes, gap widths, line widths, area differentiation thresholds, and so on, so I translated it to English to share with you here.


I’m not by any means a French speaker so if you see any problems with the translation please let me know and I will fix the graphic. (Edited 12/10/15 as per Bennett’s comment below.) I’ve left the commas instead of replacing them with periods, due entirely to laziness and my faith in your intellectual agility.


Because Halos

December 18th, 2014

Mostly, halos around labels on maps look bad. Especially when they are large and in high-contrast with the background. For example:

Halo Example Mega Size



We typically prefer what has been referred to recently as masking halos. These are fairly thin and match the background color. For example:




Any questions?


Take a Cue From Good Presenters: Allow Your Message to Shine With Great Design

July 8th, 2013

I finally got to San Diego last night after a delayed flight and am now happy to be reporting from the Esri User Conference!
There are lots of topics I could blog on today but the one thing I want to focus on is an observation about how conference presentations relate to cartography.

The presentations made at the two plenary sessions today–and no doubt in the plenary still to come this afternoon–were, without a fault, presented “well”. What does “well” mean in this context? The presenters had strong voices, fluent speech without the dreaded “ums”, well-rehearsed content, and fast-paced, well-timed visuals. Because all the presenters were outstanding in their presentation delivery skills, the audience could focus entirely on the content of the talks rather than be distracted by poor speech delivery.

How does this relate to cartography? You guessed it: an outstanding map is visual perfection; it makes map readers focus entirely on the content of the map, and the message that it is conveying, rather than obstructing them with bad design.

We all have mental “gate keepers” that disallow information from being stored if it isn’t presented correctly. Get past your map readers’ mental gate keepers by creating the most visually compelling, strong-voiced, well-researched maps that you can.

Top 10 Cartography Myths

July 2nd, 2013

The top 10 cartography myths:

  1. You have to know the full history and mathematics behind projections before you can choose one. While both of these are fascinating subjects they aren’t absolutely critical to mapping. When it comes to projections the concept of primary importance is distortion. That is, you want to recognize which projections are best in the following four categories: area, angle, distance, and direction and choose one that fits well with the purpose of your map. For medium and small scale maps the projection is less important (but not unimportant) than for large scale maps. In the case of small scale maps, in particular, aesthetics may be the ultimate influence for your choice.
  2. A robust knowledge of color theory is imperative to producing a harmonic palette. Just as with projections, while learning color theory is a worthwhile pursuit, your lack of knowledge in this area doesn’t need to preclude your success in creating a pleasing color scheme. In fact, there are many short-cuts that any introspective observer can use such as keeping an eye out for paintings, websites, posters, fabrics, and other inspirational media that have good color schemes and borrowing them for your map.
  3. All elements on a page need to be clearly separated from the other elements. Negative. The more the elements flow together the more cohesive the design appears. Separation doesn’t have to be completely absent but judicious use of white space can go a long way to providing the needed separation without the gaudy effect that a plethora of boxes create.
  4. The map must fit into the allotted space, which is usually rectangular. Some of the best maps I judged in the GISCI poster contest last year were circular and one jutted into the rectangular margin where it had data that wouldn’t quite fit. Breaking through imaginary constraints in a visual way surprises the map reader and and shows a willingness to “think outside the box”.
  5. Mercator is the best projection for webmapping. Just because Mercator is the defacto standard for most webmapping APIs doesn’t mean that it is the best. The areal distortion in the polar regions is almost inexcusable when alternatives such as the Winkel Tripel exist that handle those regions much better. While, for the most part, Mercator is what we’re stuck with for now, stay tuned to the geo-channels for when this starts to change.
  6. Don’t use more than two fonts on a map. While this is a nice rule-of-thumb, the idea that you should only use one sans-serif and one serif font on your map is not always true. Maps that are annotation-rich may require several fonts for a proper hierarchy to be achieved. If you do use more than two fonts, you must take care to maintain a visual harmony among them, which is best achieved by trial and error. Remember, in the case of fonts, visual harmony doesn’t necessarily mean that the fonts should look alike. In fact, contrast within the same style (traditional or modern) may work best.
  7. Pare the data down to the most basic possible and declutter. Decluttering is good, up to a point. Remember Donald Norman says “people prefer a medium level of complexity”. You don’t want to make your map reader feel dumb or risk not giving them enough information but you also don’t want to overwhelm them. There’s a sweet spot to hit in the middle.
  8. Only people with a design background can make creative maps. Even if you are the most hard-core analytical person you know (and you know this because you’ve certainly analyzed everyone you know), creating a work of design genius is still within your reach. Analytical-minded people already have the ability to determine what the map needs to do as well as the patience to see a design through to its completion. The creative part of the equation is accomplished through practicing creative skills with any myriad of creative activities that don’t have to take up much of your time at all (see previous posts in this blog on creativity for more information on how this works).
  9. It’s all been done before. We might be approaching some kind of apex in map design or we might still be at the burgeoning stage of new and creative map design. Either way, there is most certainly room for improvement and an increase in variety of styles and means of getting our map’s messages across.
  10. If you don’t have the right software you can’t make a decent map. No longer do we need to fret the purchase of extremely expensive software in order to turn out a map. Much of the proprietary software now offers month-to-month licensing for those who aren’t in constant need but who do require professional software from time to time. Much of the free and open source software available today is as good as, or in some cases rivals, that of the professional software. You might have to use a variety of software to achieve your goal with foss but it can be worth that extra pain up-front.

Cartographer's Toolkit

Map Making Tips, Tricks, and Inspiration